How Fast Should Stuff Unlock?

The game Magicka unlocks eight different elements in its ten minute playable intro, giving you access to 16,384 spell combinations.

And later, an M60.

Half-Life 1 and 2 don’t give you any abilities in the first ten minutes, and in general only grant you about one new weapon type every hour or two.

Obviously it depends partly on genre, but there’s more than that going on. I think developers fundamentally disagree on the question of “How far through the game should I get access to the main abilities that make it great?”

Every hour before that point, you lose some players who might have liked it if they’d got that far. I’m probably never going to get through Dead Space 2 because I’ve been playing for hours and still only have two weapons, one unexciting and the other impractical.

But every hour after that point, the player has a less exciting sense of progression, and risks getting bored with the same formula. FEAR probably fell victim to that – if you didn’t love the basic combat as much as I did, the fact that it never changed after the first few levels probably killed it.

Personally, I like to get things one at a time, but quickly early on. I will play almost anything if my toolset is changing every ten minutes.

The games that pace their unlocks slower tend to frontload the experience with a lot of scripted or story content, unique stuff that’s hard to make.

I think that’s rarely as compelling and inviting to the player as getting new abilities. I’d rather they saved the unique, story-driven stuff for after I’ve got all my tools, to stop that phase from getting repetitive. By that point I’m probably invested enough to pay more attention to it, whereas early on it’s usually unwanted noise.

What’s your sweet spot? What games do it well, and which ones don’t? I’m asking partly because this is one of the big things I haven’t decided about Gunpoint yet.

51 Replies to “How Fast Should Stuff Unlock?”

I like games such as Portal which slowly trickle their goodies in the first little half an hour, but hold off on telling you the possibilities of them. A shotgun can shoot, that’s it, but a Portal gun and its uses are open to discovery. That’s what I like, when you get all your abilities in the first section and then the game teaches your or lets you explore what they actually do throughout the whole of the game. I know even just in that final boss fight of Portal I was still discovering new things I could then apply to my second playthrough.

Personally, I find that having the abiltiies drip-fed, but, at least early on, given to me relatively quickly, is always the best way to go. Give everything to me at once, and I’m overwhelmed, just sticking to the first thing that I find works. Magicka falls prey to this more than most, as I’ve found that a steam beam is usually versatile enough to take anything down.

But, conversely, the game also litters spell books throughout the world, giving you a new set of slightly more interesting and powerful spells to learn and utilise. Rain might seem useless, until you realise you can shield yourself beforehand and still have access to lightning as it’s soaking those around you. Hey presto, super conductors.

There’s another side to the relevance of unlocks though; it’s not enough to just give me new stuff. I want to have them make my life notably easier, in a way that I can quickly understand. To use Gunpoint as an example, before getting the rewiring tool, the guards are a real pain to get around and take out. (In a good way). They’re a real threat, and you spend a lot of time figuring out how to circumvent them using the climbing before they take you out.

However, once you get the tool, you’re able to actually play with them, turning them into the vulnerable ones, and that’s made me appreciate the strength of the tool all the more. Without that preface, that weakness without the tool, I don’t appreciate it when I actually get it. That’s why the crowbar feels like mana from god in Half Life 2; you were powerless without it, and the game made that very apparent.

I would disagree that Magicka gives you all your abilities straight off. Sure, it gives you the ability to cast every spell, but you don’t know what those combinations are, or which ones are good.. The fun is in experimentation and finding what works, so really you’re receiving new abilities only as quickly as you can find them. It kept (and still keeps) everything fresh for me, as I’m always finding out new combinations and fine-tuning my tactics.

Magicka is a “one goal, many ways” system, as the only task is to move ahead through the story (or kill everything in the challenges). Compare that to a “one goal, few ways” game like FEAR or a “many goals, many ways” game (some strategy games, e.g. HOI3).

I think we can sort of look to Oblivion for this. Everything you could ever do in that game opened up the moment you started playing it and that was really unsettling to most gamers. If you let it, you would take a wild ride to just about any corner of the country and you could find any random/cool/dumb thing you wanted to without any motivation to really do so.

Personally, I like the everything at the start approach, especially in a deep system. Feeling crippled is pretty annoying for me. Getting a new gun every hour or two in HL2 was great because it was a linear FPS and there never felt like there was a situation where you couldn’t handle with what you already had. Route Canal didn’t feel like it needed the AR2 to feel better.

I guess what I’m saying is that I don’t like feeling crippled and that’s what puts me off with games like The Force Unleashed or Prototype where at the start of the game everything is hard because you can’t do shit and the end is a joke because you can do anything. No unlock or progressive tool should make anything else less useful or be more fun than the others.

I like the way Black Ops handles unlocking MP weapons, as I can bypass things that sound boring or useless, but most of the guns are pretty samey. For single-player stuff the Ratchet and Clank series does it really well, partly because all of the weapons are imaginative and fun, and partly because you rarely go more than half an hour without getting a new ability. And when you factor in upgrading weapons through use you get loads of new stuff and always something else to look forward to.

I think a balance of both quick, regular rewards and more infrequent rewards that have to really be earned. You want crumbs to keep the player along from moment to moment and keep them playing, with a larger overarching possible reward or unlock.

Phill has a point that withholding tools can make the player appreciate them more. Kind of like making someone code a web page by hand before letting them use a WYSIWYG editor, so they understand the underlying principals. For example, Bad Company 2 had shock paddles, repair tools and medkits as unlocks, with the logic that a noob would have their hands full just figuring out how to move and shoot, without burdening them with more complex tasks.

More than a few games (Assassin’s Creed, for one) start the player out with all their badass abilities then strip them after the first mission so the player can see what they’re working towards, which can work if the stripping away isn’t too artificial. And if you get a new tool in the last few minutes, you risk the player not being able to get much use out of something you put a lot of time into.

Losing your abilities at the start is kind of the worst of both worlds though, isn’t it? Noobs get overwhelmed by having a crazy number of options and controls, but they also don’t get to enjoy the flexibility of having everything unlocked because it’s taken away before they get used to it.

Presumably it’s meant to solve the problem of losing interest before you even know what the full ability set is – at least you know what you have to look forward to. But I think there are smarter ways to do that. In Gunpoint, I’m probably going to have a shop that shows everything you can ever get, some of it too pricey to afford at first.

1) Start with a decent set of abilities, which the game makes you use, so you get some idea of what you’ll be capable of.
2) Lose ’em fighting an overpowered boss.
3) Regain abilities slowly throughout the game (about one per hour, or 1.5 abilities per boss fight), eventually greatly surpassing your initial power, defeating previously overpowered boss along the way to underline the point.
4) Do all of the above without having anyone tell you what you need or where to go – just reward exploration.

They key to why this works is because the Metroid titles use one large persistent world. Each time you get an item/ability, it not only opens up the next step of the story-driven-quest, it also makes you realise you can now go back to room X and reach the thing Y that was previously out of range, etc. Giving you a taster of your abilities at the beginning and making it clear that you’ll regain them feeds into this – you’ll see things and thing “Ah, can’t get that now – I’ll come back when I have the grapple beam” or whatever.

The Zelda titles work similarly, but are a bit more signposted, and you know you’ll only get a new item/ability in the course of clearing a dungeon stage.

My problem with the Magicka model is that it doesn’t force experimentation on me. I like to play around with things, but if I’m in the middle of a fight, I’m going to go with the most efficient option, not the most interesting one, and that means I’m barely scratching the surface of the system.

It’s all about balancing your audience’s patience and delight in each phase of unlocks (moreso, I think, than the Metroid/Assasin’s Creed/Prototype model of “Here’s where you’ll be eventually, now let’s strip that away).

Half-Life 2 is a great example of this as a game with a bunch of discrete phases that are triggered by changing the tools at your disposal. There’s the scripted chase stuff at the start, then the cautious, out-numbered/out-gunned sequences that culminate in taking out the chopper. Then you introduce a new tool – the grav gun – and cut down on ammo to create a new phase about using the environment against enemies that primarily use melee.

Then, the player’s arsenal is expanded and powered up so that you can do a game about big, set-piece-y battles against large squads of enemy troopers. And then the reward is the last change, to crazy physics omnipotence with the super-gravity gun.

The later phases of that aren’t “better” than the previous ones, they’re just different games working within the same framework. Designers need to check whether each phase of their game is fun to play, and then gauge how long a player needs to be in it to a) learn effectively how to play it, and b) get the most fun out of it.

@Tom: You’re probably right there, I never particularly cared for that type of intro, mainly because taking away the power is usually contrived, and common enough that it’s almost expected. Shops aren’t a bad idea, and they have some precedent in Spelunky, for example. But with that, you have to make it clear exactly what the shiny things in the store actually do. Maybe a “the first hit’s free” kind of thing, if the store items are expendable.

Far Cry 2 sort of had weapon demos, where there would be a really worn out example of a powerful late game weapon like the multi-round grenade launcher, which would break quickly but give you a feel for what’s waiting for you.

In Super Mario 64 you start the game able to do every move available to you. Throughout the levels there are signs you can read that teach the moves to you when you first need to use a specific one to progress, but if you are playing the game for a second time you don’t need to read them and have access to the full move set (minus the ‘caps’). Also, if you are comfortable and know all of the moves, when replaying you can find alternate ways to complete earlier levels more quickly and with finesse (See Super Mario 64 speedruns).
Conversely, In Banjo Kazooie, you have to unlock each different ability such as the special walk for going up steep hills or flying. So while playing it from the beginning again can feel tedious and limiting, the game gets to do the whole Metroid thing and use the unlocking of abilities to gate off areas of the world, which you can then come back too.

Can’t think of the ideal game right now. But what I’d want is – unlocking of essential weapons/abilities ASAP, one after another and the unlocking of special stuffs as the game progresses and depending on the situations.

In Dead Space 2, I’m happy that I get to get my hands on the Plasma Cutter and Pulse Rifle pretty early – two weapons I find very useful.

In singleplayer games, I feel you should get a new weapon, gadget every mission or so for the first 4 missions, then they can lower the amount. It’s important to give items early on, because it allows the later levels to be more complex and fun, while allowing the earlier levels to be easier and act as tutorials for the items you receive.

In Multiplayer games, have a burst of unlocks for the first 10 or 20 levels, then lay off them until you get to at least Level 35.

But in the grand scheme of things…. I’ve never felt that “rate of unlocks” was something that really mattered. If the game is good enough, it doesn’t matter.

It’s an interesting point, I actually wrote a post tangentially related to this, but was specifically sparked by the detective vision mode in Batman: Arkham Asylum – which you have available to you all the time. I was trying to feel out the problem of items or abilities requiring imposed limitations to be fun.

Personally I love that Magicka gives you all the basic spells up front, and still provides a series of unlocks in the Magicka spells which you have to progress to obtain. It’s almost the best of both worlds. You have a huge toolbox of spells and combinations to discover and master, all available upfront, and you have an ever expanding set of tools with each new Magicka you find which helps the sense of progression.

When it comes to Dead Space 2, what’s interesting is that basically all the weapons are just about the same as in the first game, and that you could completely ignore them all after getting the first two (which I did) and complete the game just fine. It’s too bad because the precision shooting mechanic is cool, and yet I don’t find myself interested in experimenting with the weapons at all.

I think Jedi Academy did the unlocking of force powers pretty well actually. (In fact I think Jedi Academy is often underrated) You got one point to spend on force powers at the start of each mission, and you had a pretty large choice of light and dark force powers to spend those points on. Each power could be upgraded up to three times, with the basic version of the power providing pretty simply functionality, and each stage adding new effects or further increasing the power.

The force lightning power for instance, starts off simply firing one quick little blast of lightning straight forwards, it will hit one enemy and not do much damage. Once you’ve upgraded it to rank three however, you can put your weapon away and fire it out of both hands in a massive arc, frying everything in an enormous cone infront of you.

The great thing about this is that you can have it at rank three by the third mission, meaning you can feel extremely powerful very early on. Or, you could put points into a wide spread of powers, giving you more flexibility but with less potency.

The system which elevates this even further in my eyes is the extra force powers you have, the so called “neutral” force powers. These neutral powers are the old staples such as push, pull, speed, sense and jump. These upgrade three times in a similar way to the light / dark powers, however you cannot upgrade them yourself, instead they each increase in power by one point at the end of each act, meaning that by the end of the game you really feel like a powerhouse.

What makes this system so good is the way that it paces the game. By the end you are slamming multiple enemies into walls and moving so quickly that time seems to slow down, but the way you can upgrade your light / dark powers means that you don’t feel totally useless at the start of the game either.

It is perhaps a little strange that you can pick enemies up with force grip and fling them around rooms and smash them into walls before you have mastered “basic” powers such as running faster or jumping higher, but as a gamey conceit it works very well, and means that you always feel like your power is increasing, while not unbalancing the game by making you feel totally incompetant after the first few missions and more powerful than Yoda and Darth Vader combined at the end.

Good writeup. I’d forgotten that your neutral powers levelled up automatically, I guess that’s because they were sometimes required at a certain level for puzzles/level geometry.

I think you’ll like Deus Ex 3.

Jedi Knight 1 is an interesting example of Getting Your Sword incredibly late – felt like a whole game with blasters and crossbows before you find your father’s lightsaber. I wanted a first-person Star Wars game badly enough that it never bothered me – shooting dudes with blasters felt like the game. It’s good that they made that saberless section shorter with each new game, but each time I still enjoyed it.

Half-Life 2 and Metroid Prime are two games among my favorites and they both provide consistent new abilities throughout the game. Having a store is a good option too because it provides gamers with options of what to buy and also encourages playing the game to its fullest to get enough credits to buy the expensive ability/weapon/thingy.

I think it really depends on the type of game, I know that’s not helpful to you. With a game about you being a mighty wizard you want alot of spells straight off. If you’re trying to survive a zombie outbreak you want to keep the tension up by only giving you a pea shooter with 4 rounds in it.

However I’ve always enjoyed “shops” in games, especially ones with upgrades. They limit your growth by making you decide on one thing to upgrade but give you the choice of what you want to upgrade, tailoring the experience to your tastes.

hey there tom! interesting article, and it’s something i am exploring in a flash-based RPG i’m working on. i think it’s important to give players something cool early on, and then unlock even more awesome versions of it as you progress.

for my game, i’m going to try rune-combination based magic, kinda like magicka, but with steadily more runes added, and the existing runes can be upgraded, AND you can add effects to it later (multiple strikes, etc).

Nice, that sounds like fun. I love Magicka, but I think I would have discovered more interesting combinations if the elements had been given to me more gradually. As Phill says, with too many options at once us players tend to stick to the first thing that works.

Funny you say that about the saberless bits of Jedi Knight! Jedi Knight 2 was one of the first PC games I bought and I have always held a very special place in my heart for it… However I went back and played through both that and Jedi Academy recently (having played through both a good few times) and I found that JK 2 has really not aged well, the saberless sections in particular.

The section pre lightsaber in JK 2 feels like it drags on and on, and back when I first played it through (I was about thirteen) I didn’t really look at it with a very critical view, I was too busy thinking “pewpew starwars”, but those first few missions really are terrible now. Endless identical grey corridoors with legions of stupid stormtroopers, and mission objectives like “find the blue, green and red keys to unlock this arbitrarily colour coded door.”

I found the shooting was weak and the locations weren’t great either, but the story was much better than Jedi Academy’s, even if your arch enemy was a mutant bi-pedal dinosaur. Jedi Academy however gave you your lightsaber right from the off, and I enjoyed it far more because of it, and have probably played through Jedi Academy more than Jedi Knight 2 now. Whenever I look at Jedi Knight 2 on my shelf I remember those horrendous pre lightsaber sections and think “oh god no”.

@Chris
The original FEAR remains, in my opinion, one of the best shooters we’ve seen in a long time on the PC. it may have suffered from not really changing it’s enemies, or varying it’s locations or combat bubbles, but my god was it’s combat satisfying. I think it really nailed the “feel” of shooting something in FEAR, in that your guns felt colossally powerful and made great noises when you pulled the trigger. Oh and slo-mo kicking people was hilarious, especially if you did the low slide kick thing, and it slammed someone so hard into a wall that it killed them, leaving a smeary trail of blood down the wall as they dropped…. In slow motion.

I liked the Halo mechanic. You don’t tend to get shot at with anything that you can’t then pick up and shoot back. There are a few exceptions. But I’ve never got to an area and thought this isn’t fair, or being annoyed that I didn’t bring the right weapons or conserve the right ammo from the level before.

Magicka is great. It’s my favourite game of the moment. I really enjoy that you can use some of you most powerful combinations from the very beginning. It’s the whole feeling of it just letting you have free-reign which I love. You don’t need to manage a “mana” bar or wait till the last but one level to use the fun combinations, or play through the game 20 times to have the XP to pull off the big spells it’s right there from the beginning, letting you destroy things in fun ways.

Crackdown would be another game with yet another style. You have all the abilities, but they level up as you use them. I suppose this contradicts some of what I picked out in magicka. But I enjoy this style too. Going from beating people with a car door to beating people with a car is great fun.

Yeah, the limitless mana is the real revelation in Magicka. They found a smarter way to limit your power: how quickly you can think creatively on your feet, and the strategic choices you make about the form your spell takes and what it will hit. The ‘weight’ of Arcane beams in particular is such a great piece of design, making the beam feel like a devastating force of nature you’re only just able to control, while also preventing it from being a game-ending win button.

FEAR: It’s funny that its two problems are not being varied enough and, in the end, trying to vary. The flying robots and dumb ghosts are just dismal. I forget exactly where it is, but I figured out the point you can just stop playing and not miss anything good, so I’d just replay the first five hours or so many, many times.

One of my favourite playthroughs was as a ninja cop: I’m only allowed to use a single pistol and kung-fu. Surprisingly doable and very different. There should have been a gas-leak level that forced you to stop using guns for a short while – most people never discovered how good the melee was.

I have to admit, I enjoyed Dead Space 2 a lot but I don’t think it’s anything to do with the weapons, frankly. You can get through the whole thing with the first weapon, so to me I think the dripfeed is more in the suits you unlock getting progressively more cooler and in getting enough power nodes to upgrade your existing weapons. Which in itself I suppose is another way of doing the item drops – instead of giving you new stuff, it seems you’re supposed to be more interested in how your existing stuff is improving.

I’m not sure whether it would work for you, but I admit I’ve just finished my second playthrough of the game, purely to get enough Power Nodes to max out the four weapons I’ve bought (Plasma Cutter, Ripper, Line Gun and Javelin Gun) I’ve not even purchased any of the others yet, and out of those I think I find the Javelin the most fun because well… I’m a sucker for impaling weapons.

Give me cool stuff from the start, I want to be able to play around and have fun with a big toolbox straight away. If I mess up because I haven’t quite grasped exactly how everything works, it doesn’t matter – just compensate for that.

Here’s the important thing though: show me even cooler stuff that I want. That way I know it’s coming, I can work towards it, and when I get it I get the emotional pay off of “sweet I’ve got the thing”. It doesn’t really matter on the pacing of this, especially if it’s just something like an aesthetic change.

To use your example Magicka sort of does this: you get cool stuff from the start and then you’re slowly drip fed spells which you get from beating bosses that use that spell against you first.

ithink one of the problems with the half-life 2 approach is that by the time you have some later weapons, the crowbar and pistol are both useless for anything other than humiliating your foes. it doesn’t inspire “look how far i’ve come” in me so much as “what on earth am i still doing carrying this junk around?” the early tools, to my mind, aren’t so much important in timing as in function- if its purpose is exciting and useful enough to begin with as well as throughout the game, it’s fine to only be holding on to your only weapon for an hour or so.

I think PlumberDuck makes a good point on HL2. HL2 has a linear story and the developers did a good job thinking through how different weapon and enemy match ups will give you completely different gameplay at different stages. For that reason it worked well for HL2, but those lessons just aren’t applicable to an open world game. The more choices you give someone, the less ability you have to optimize for each of those choices. It’s not that either linear story or open world is better, just the same design concepts don’t apply.

The thing that irks me about the Dead Space games is how it expects you to hang on to an ammo-starved weapon until you find or purchase an absurd amount of power nodes, a commodity in extremely short supply. Case in point: the Javelin Gun. Using it is all but pointless until you’ve sunk 20+ of the nodes into it, at which point it abruptly becomes laughably overpowered. I tore through the hardest difficulty in a day using only it and the also insultingly powerful Ripper.
This may because the game never really gets “difficult” per se, it just gets annoying. There’s no real final bossfight, you just sort of run away from what is essentially a reskin of one of the big bads from the first game while the annoying black goopy monsters pester you.

Oh man, my friend picked up the FEAR pack recently. He and I came to the conclusion that the games were “retarded”. Foolishly lured in by nostalgia, I reinstalled one of the games, but only got about 2 hours in before I was overwhelmed by the brutal drabness of it and had to uninstall it again. It’s one of those games that just ends up feeling like a chore to play by the end.

There used to be a fine tradition of starting with an infinite ammo puny handgun which you’d have to resort to when all the ammo ran out. In our house such weapons were affectionately called ‘Spud Guns” or “Spuddy”. There was great kudos to be had for spuddying each other or big enemies. Somewhere along the way spuddies gave way to start off with automatic or semi automatic weapons which was a sad change indeed.

I can’t help but think of Dark Forces from back in the 90s. You got a new weapon every level or two (there were something like 10 weapons spread over 12 levels, though you got 3 of those weapons in the first level, including an-almost Spuddy (chewed through ammo very slowly, but still used it up).

It was well paced, but more importantly, you could find many of these weapons a level “early” if you were a good enough player, as many were dished out fairly obviously on the level you were “supposed” to get it on, but would be avaliable somewhere in a hidden room on a level preceeding it, some of which were exceptionally hard to get to, let alone find.

Plus, some of the weapons had secondary fire that only worked with special ammo which might be findable only on a level or two, so things still kept switching up as you went through it.

Oh, and forgot to mention. Spuddy in Dark Forces was still useful even in the late game, as there wasn’t any form of sniper weapon in Dark Forces, and Spuddy had the least spread over long distances (and a bit of auto-aim, if I remember correctly), making it great for slowly picking off Stormtroopers in certain situations.

All these references to FEAR remind me of a great many wonderful hours spent with roommates in college. I favored the dual pistol sprinting ninja-fu approach in multiplayer, and always enjoyed myself.

My favorite memory was early on in the multiplayer before too many patches came out: my roommate and I were both playing on the same server and figured out that remote mines stuck to a teammate didn’t kill them. The rest of the evening was spent with one person hiding in a corner with the detonator while the other ran around like a crazy person jumping into a group of enemies tactically making their way across the map. They yelled fire, I pressed the button, everyone died. Roommate makes his way back to be filled with stickies again. A few weeks later it was patched out of the game; but for a short glorious while, there were a large number of explosions and very surprised tactical FPS players on the FEAR servers :)

FEAR also had a fantastic free to play multiplayer component – FEAR Combat, which was really exceptional. I always think the best test of a first perosn shooter is how much fun it is to simply play in a deathmatch, as that really boils down to the basic mechanics of pulling the trigger, and shows off how weighty the guns feel and how tactile the combat is in general – FEAR was superb in those regards.

Also, yes, the FEAR expansions were really really weak, which is sad considering how good the first game was. I’ve never really thought that expansion packs were a good idea for FPS games, it has always struck me as a better idea for an RTS – where you can add new units or factions and new maps etc.

Not to interrupt the great discussions going on above, but I’m curious on the math behind the possible combinations. Tom states 16,384 spell combinations, while the Magicka wiki site below lists it as 1,123 possible combinations… I’m more inclined to believe Tom’s number, but can’t come up with the formula to support the 16,384 number as I’m terrible at math. For that matter, is the 1,123 number actually correct? There are 2 additional elements you can get by combining the 8 existing elements (water and fire for steam, cold and water for ice), and quite a few of the elements cancel each other out (water and lighting, ice and fire, life and arcane, etc), so the formula isn’t as simple as I thought, and I can’t come up with one that satisfies. Permutations and Combinations formulas don’t seem to apply here… Any math majors out there?

@Chris R
If none of the elements cancelled each other (e.g. arcane and life), and none of them combined (e.g. a spell with fire and water), and you could cast multiple shield elements in one spell then there would be 3003 possible combinations of the 10 elements (and casting the puff of air with 0 elements). With all the exclusions that exist I think 1123 is a fair number, but I don’t know enough about multiset coefficients and excluding certain combinations. (I may not be heading down the right path with my maths. It’s been ages and I didn’t have the pleasure of studying at uni level.)

And I would argue that technically it’s 1123 + 21 magicks (22 if you have the DLC)

Mine was meant to be the number of spells you can try rather than just the ones that’ll do something useful, so theirs is almost certainly correct. I didn’t factor in cancellations or the extended string length you can get with elements that collapse. I don’t know of an easy way to term the cancellations in an expression, since I’m not completely familiar with all the conditions in which they cancel out – it’s possible to get conflicting elements in the same spell if you order them right.

I really loved the pacing of both Half Life 1 and 2. Every moment regardless of your inventory is driven by the overwhelming need to see what’s going to happen next. Actually, even knowing what’s going to happen next doesn’t kill the appeal – I’ve played through both 2-3 times. I particularly thought saving the combine-killing gravity gun variant to last was genius, giving that out too early would have killed the game. Maybe the trick is having enough to get by while there are still interesting situations to scrape through.